The present invention relates a high frequency dielectric ceramic compositions.
Recently, with the rapid development in a mobile communication and a satellite communication, a high frequency dielectric ceramics is in a high demand as a material for a high frequency integrated circuit or a dielectric resonator.
Major characteristics of the dielectric ceramics used for a high frequency includes a high dielectric constant (∈1), a quality factor (Q) and a stable and tunable temperature factor (xcfx841) of a resonance frequency.
Representative high frequency dielectric compositions which have been widely known up to now are (Zr, Sn,)TiO4 group, BaOxe2x80x94TiO2 group, (Mg, Ca)TiO3 group, and Baxe2x80x94(Zn1/2Ta2/2)O3, Ba(Mg1/3Ta2/3)O3, Ba(Zn1/3Nb2/3)O3 as Ba-peropskite group.
However, these compositions are disadvantages in hat they are mostly fired at a high temperature of 1,300-1,500xc2x0 C. upper sum is not easy, a dielectric constant is low or a high-priced material should be used.
Besides, lately, advancement of a portable information communication devices lead to development of various types of boards and multi-chip module (MCM) by a multilayer chip high frequency devices or low temperature co-firing ceramics (LTCC), and a research and development of a low temperature firing high performance high frequency ceramics are conducted accordingly.
However, there are problems that the performance of the high frequency characteristic is considerably degraded such as, for example, most of them are not sufficient in terms of density when being fired at a low temperature, a dielectric constant is degraded according to addition of a firing material, a quality factor is degraded and a temperature factor is changed.
In addition, silver conduct or copper conduct with a small high frequency loss and a cofiring available low temperature firing high frequency dielectric ceramic are very rare.
Therefore, an object of the present invention is to provide a dielectric ceramics composition which can be fired at a very low temperature but has an excellent high frequency dielectric characteristic of various temperature compensation characteristics according to a high quality factor, a dielectric constant, a stable temperature factor and a composition, and can be implemented at a low cost.
Another object of the present invention is to provide a dielectric ceramics composition which can employ Ag, Cu, their alloy or a Ag/Pd alloy as an internal electrode and thus be used for various high frequency devices, such as a stacked chip capacitor, a stacked chip filter, a stacked chip capacitor/inductor composite device and a low temperature firing board, a resonator and a filter or a ceramic antenna.
In order to achieve the above objects, there is provided a dielectric ceramics composition which is constructed by combining 1 mole of (Zn1-xMx)TiO3 and yTiO2(Oxe2x89xa6yxe2x89xa60.8 and fired at a low temperature of 925-1,100xc2x0 C., its preparation method, and a high frequency dielectric ceramics device using the same. In this respect, xe2x80x98Mxe2x80x99 is one of Mg, Co, Ni, xe2x80x98xxe2x80x99 is 0xe2x89xa6xxe2x89xa60.6 in case of Mg and xe2x80x98xxe2x80x99 is 0xe2x89xa6xxe2x89xa61 in case of Co, and 0xe2x89xa6xxe2x89xa61 in case of Ni